Manufacturers of internal combustion engines are continuously attempting to improve the efficiency and emissions output of internal combustion engines. In diesel engines, a large amount of research has been done to reduce NOx output of an engine, through the use of improved fuel injectors and injection control. An injector tip typically includes a sac portion defined by an internal nozzle chamber and an exterior portion protruding from the end of the tip. A plurality of nozzle passages extend from a sac chamber through the sac to an outer sac wall. High pressure fuel is forced into the sac chamber, which is then sprayed into a combustion chamber. Often the spray of fuel does not mix evenly with combustion air within the combustion chamber. This creates uneven temperatures within the combustion chamber and causes inconsistent burning, resulting in emissions fluctuations.
In efforts to improve combustion and reduce emissions, tip geometry may be altered to improve atomization and distribution of the spray pattern within the combustion chamber. An improved spray distribution increases mixing of fuel and combustion air, in turn creating more evenly distributed temperatures throughout the combustion chamber.
Many manufacturers have altered geometry of injector tips in efforts to improve efficiency and emissions of engines. U.S. Pat. No. 4,106,702 issued to Gardner et al. illustrates a common tip and nozzle arrangement. Although designs similar to this are still being used, attempts to improve distribution of fuel spray in the combustion cylinder continue.
The present invention is directed to overcoming one or more of the above identified problems.